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From: Rick Edgecombe <rick.p.edgecombe@intel.com>
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Subject: [PATCH] mm: Remove mm argument from mm_get_unmapped_area()
Date: Mon,  6 May 2024 09:07:47 -0700
Message-Id: <20240506160747.1321726-1-rick.p.edgecombe@intel.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

Recently the get_unmapped_area() pointer on mm_struct was removed in
favor of direct callable function that can determines which of two
handlers to call based on an mm flag. This function,
mm_get_unmapped_area(), checks the flag of the mm passed as an argument.

Dan Williams pointed out (see link) that all callers pass curret->mm, so
the mm argument is unneeded. It could be conceivable for a caller to want
to pass a different mm in the future, but in this case a new helper could
easily be added.

So remove the mm argument, and rename the function
current_get_unmapped_area().

Fixes: 529ce23a764f ("mm: switch mm->get_unmapped_area() to a flag")
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://lore.kernel.org/lkml/6603bed6662a_4a98a2949e@dwillia2-mobl3.amr.corp.intel.com.notmuch/
---
Based on linux-next.
---
 arch/sparc/kernel/sys_sparc_64.c |  9 +++++----
 arch/x86/kernel/cpu/sgx/driver.c |  2 +-
 drivers/char/mem.c               |  2 +-
 drivers/dax/device.c             |  6 +++---
 fs/proc/inode.c                  |  2 +-
 fs/ramfs/file-mmu.c              |  2 +-
 include/linux/sched/mm.h         |  6 +++---
 io_uring/memmap.c                |  2 +-
 kernel/bpf/arena.c               |  2 +-
 kernel/bpf/syscall.c             |  2 +-
 mm/mmap.c                        | 11 +++++------
 mm/shmem.c                       |  9 ++++-----
 12 files changed, 27 insertions(+), 28 deletions(-)

diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index d9c3b34ca744..cf0b4ace5bf9 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -220,7 +220,7 @@ unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, u
 
 	if (flags & MAP_FIXED) {
 		/* Ok, don't mess with it. */
-		return mm_get_unmapped_area(current->mm, NULL, orig_addr, len, pgoff, flags);
+		return current_get_unmapped_area(NULL, orig_addr, len, pgoff, flags);
 	}
 	flags &= ~MAP_SHARED;
 
@@ -233,8 +233,9 @@ unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, u
 		align_goal = (64UL * 1024);
 
 	do {
-		addr = mm_get_unmapped_area(current->mm, NULL, orig_addr,
-					    len + (align_goal - PAGE_SIZE), pgoff, flags);
+		addr = current_get_unmapped_area(NULL, orig_addr,
+						 len + (align_goal - PAGE_SIZE),
+						 pgoff, flags);
 		if (!(addr & ~PAGE_MASK)) {
 			addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
 			break;
@@ -252,7 +253,7 @@ unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, u
 	 * be obtained.
 	 */
 	if (addr & ~PAGE_MASK)
-		addr = mm_get_unmapped_area(current->mm, NULL, orig_addr, len, pgoff, flags);
+		addr = current_get_unmapped_area(NULL, orig_addr, len, pgoff, flags);
 
 	return addr;
 }
diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c
index 22b65a5f5ec6..5f7bfd9035f7 100644
--- a/arch/x86/kernel/cpu/sgx/driver.c
+++ b/arch/x86/kernel/cpu/sgx/driver.c
@@ -113,7 +113,7 @@ static unsigned long sgx_get_unmapped_area(struct file *file,
 	if (flags & MAP_FIXED)
 		return addr;
 
-	return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags);
+	return current_get_unmapped_area(file, addr, len, pgoff, flags);
 }
 
 #ifdef CONFIG_COMPAT
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 7c359cc406d5..a29c4bd506d5 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -546,7 +546,7 @@ static unsigned long get_unmapped_area_zero(struct file *file,
 	}
 
 	/* Otherwise flags & MAP_PRIVATE: with no shmem object beneath it */
-	return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags);
+	return current_get_unmapped_area(file, addr, len, pgoff, flags);
 #else
 	return -ENOSYS;
 #endif
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index eb61598247a9..c379902307b7 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -329,14 +329,14 @@ static unsigned long dax_get_unmapped_area(struct file *filp,
 	if ((off + len_align) < off)
 		goto out;
 
-	addr_align = mm_get_unmapped_area(current->mm, filp, addr, len_align,
-					  pgoff, flags);
+	addr_align = current_get_unmapped_area(filp, addr, len_align,
+					       pgoff, flags);
 	if (!IS_ERR_VALUE(addr_align)) {
 		addr_align += (off - addr_align) & (align - 1);
 		return addr_align;
 	}
  out:
-	return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags);
+	return current_get_unmapped_area(filp, addr, len, pgoff, flags);
 }
 
 static const struct address_space_operations dev_dax_aops = {
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index d19434e2a58e..24a6aeac3de5 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -455,7 +455,7 @@ pde_get_unmapped_area(struct proc_dir_entry *pde, struct file *file, unsigned lo
 		return pde->proc_ops->proc_get_unmapped_area(file, orig_addr, len, pgoff, flags);
 
 #ifdef CONFIG_MMU
-	return mm_get_unmapped_area(current->mm, file, orig_addr, len, pgoff, flags);
+	return current_get_unmapped_area(file, orig_addr, len, pgoff, flags);
 #endif
 
 	return orig_addr;
diff --git a/fs/ramfs/file-mmu.c b/fs/ramfs/file-mmu.c
index b45c7edc3225..85f57de31102 100644
--- a/fs/ramfs/file-mmu.c
+++ b/fs/ramfs/file-mmu.c
@@ -35,7 +35,7 @@ static unsigned long ramfs_mmu_get_unmapped_area(struct file *file,
 		unsigned long addr, unsigned long len, unsigned long pgoff,
 		unsigned long flags)
 {
-	return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags);
+	return current_get_unmapped_area(file, addr, len, pgoff, flags);
 }
 
 const struct file_operations ramfs_file_operations = {
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 91546493c43d..c67c7de05c7a 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -187,9 +187,9 @@ arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 			  unsigned long len, unsigned long pgoff,
 			  unsigned long flags);
 
-unsigned long mm_get_unmapped_area(struct mm_struct *mm, struct file *filp,
-				   unsigned long addr, unsigned long len,
-				   unsigned long pgoff, unsigned long flags);
+unsigned long current_get_unmapped_area(struct file *filp, unsigned long addr,
+					unsigned long len, unsigned long pgoff,
+					unsigned long flags);
 
 unsigned long
 arch_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
diff --git a/io_uring/memmap.c b/io_uring/memmap.c
index 4785d6af5fee..1aaea32c797c 100644
--- a/io_uring/memmap.c
+++ b/io_uring/memmap.c
@@ -305,7 +305,7 @@ unsigned long io_uring_get_unmapped_area(struct file *filp, unsigned long addr,
 #else
 	addr = 0UL;
 #endif
-	return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags);
+	return current_get_unmapped_area(filp, addr, len, pgoff, flags);
 }
 
 #else /* !CONFIG_MMU */
diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c
index 4a1be699bb82..054486f7c453 100644
--- a/kernel/bpf/arena.c
+++ b/kernel/bpf/arena.c
@@ -314,7 +314,7 @@ static unsigned long arena_get_unmapped_area(struct file *filp, unsigned long ad
 			return -EINVAL;
 	}
 
-	ret = mm_get_unmapped_area(current->mm, filp, addr, len * 2, 0, flags);
+	ret = current_get_unmapped_area(filp, addr, len * 2, 0, flags);
 	if (IS_ERR_VALUE(ret))
 		return ret;
 	if ((ret >> 32) == ((ret + len - 1) >> 32))
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 2222c3ff88e7..d9ff2843f6ef 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -992,7 +992,7 @@ static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr
 	if (map->ops->map_get_unmapped_area)
 		return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
 #ifdef CONFIG_MMU
-	return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags);
+	return current_get_unmapped_area(filp, addr, len, pgoff, flags);
 #else
 	return addr;
 #endif
diff --git a/mm/mmap.c b/mm/mmap.c
index 83b4682ec85c..4e98a907c53d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1901,16 +1901,15 @@ __get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
 	return error ? error : addr;
 }
 
-unsigned long
-mm_get_unmapped_area(struct mm_struct *mm, struct file *file,
-		     unsigned long addr, unsigned long len,
-		     unsigned long pgoff, unsigned long flags)
+unsigned long current_get_unmapped_area(struct file *file, unsigned long addr,
+					unsigned long len, unsigned long pgoff,
+					unsigned long flags)
 {
-	if (test_bit(MMF_TOPDOWN, &mm->flags))
+	if (test_bit(MMF_TOPDOWN, &current->mm->flags))
 		return arch_get_unmapped_area_topdown(file, addr, len, pgoff, flags);
 	return arch_get_unmapped_area(file, addr, len, pgoff, flags);
 }
-EXPORT_SYMBOL(mm_get_unmapped_area);
+EXPORT_SYMBOL(current_get_unmapped_area);
 
 /**
  * find_vma_intersection() - Look up the first VMA which intersects the interval
diff --git a/mm/shmem.c b/mm/shmem.c
index f5d60436b604..c0acd7db93c8 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2276,8 +2276,7 @@ unsigned long shmem_get_unmapped_area(struct file *file,
 	if (len > TASK_SIZE)
 		return -ENOMEM;
 
-	addr = mm_get_unmapped_area(current->mm, file, uaddr, len, pgoff,
-				    flags);
+	addr = current_get_unmapped_area(file, uaddr, len, pgoff, flags);
 
 	if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
 		return addr;
@@ -2334,8 +2333,8 @@ unsigned long shmem_get_unmapped_area(struct file *file,
 	if (inflated_len < len)
 		return addr;
 
-	inflated_addr = mm_get_unmapped_area(current->mm, NULL, uaddr,
-					     inflated_len, 0, flags);
+	inflated_addr = current_get_unmapped_area(NULL, uaddr,
+						  inflated_len, 0, flags);
 	if (IS_ERR_VALUE(inflated_addr))
 		return addr;
 	if (inflated_addr & ~PAGE_MASK)
@@ -4799,7 +4798,7 @@ unsigned long shmem_get_unmapped_area(struct file *file,
 				      unsigned long addr, unsigned long len,
 				      unsigned long pgoff, unsigned long flags)
 {
-	return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags);
+	return current_get_unmapped_area(file, addr, len, pgoff, flags);
 }
 #endif
 

base-commit: 9221b2819b8a4196eecf5476d66201be60fbcf29
-- 
2.34.1